Counterbalance crank for pumping units



27, 1938. w. c. TROUT COUNTERBALANCE CRANK FOR PUMPING UNITS Original Filed July 12, 1934. 2 SheetsSheet l WALTER GTRour Dec. 27, 1938 W. c. TROUT 2,141,424

COUNTERBALANCE CRANK FOR PUMPING UNITS Original Filed July 12, 1934 2 Sheets-Sheet 2 r 30 A still fu th r o j t of t invention is t p In this Fig. 1 form of the invention it will be so Patented ee.27,193s 2 14 UNITED: STATES. PATENT oFF cE COUNTERBALANCE CRANK FOR PUMPING UNITS Walter G. Trout, Lufkin, Tex, assignor to Lufkin I Found1y& Machine Company, Lufkin, Tex, a

corporation.

. Application 'July 12, 1934, Serial No. 734,753

Renewed January 29, 1937 1 Claim. (Cl. 74591) The invention relates to an improvement in In the embodiment'shown in Figs. '1 and 2 an counter-balanced cranks for oil well pumping elongated body 33is adapted to be mounted upon units.v a drive shaft and is provided with a plurality In the pumping of oil wells'it is desirable'to of crank pin openings 32, 130 permit the changcounter-balance the load on the reciprocating ing of the stroke of the counter-balance crank. 5 walking beam so that a minimum of power will Slots or grooves 44 and 45 are formed on one side benecessary and a smoothness of operation 010- of the body 33 and adjacent its edges to receive tained. At the same time it is also desirable connecting bolts l5 which pass through cover to release the counter-balanced weight from the plate 4% and are provided with nuts 68.

crank arm or pumping mechanism so that the The counter-weight in this modification is 10 pumping unit may be used for removing the made up of a plurality of parts, but includes the pump or tubing from the well, or in otherwise base 35 through which the connecting bolts i5 performing what is known as servicing operaare arranged to pass. This base 35jeXtends betions. e yond the body 33 at each side and is arranged to One-of the objects of the invention is to proreceive a plurality oi plates 31 which are held in 15 vide a combination crank and counter-balance position by means of the bolt and nuts 38. In arm wherein the counter-balance may be adorder to adjust the counter-balance weight so justed longitudinally of the crank arm and inthat it will perform the proper balancing action, creased in size as desired in order to obtain the it is sometimes desirable to adjust the weight necessary counter-balancing action. radially with respect to the crank. With this in 20 Another object of the invention is to provide mind, a plurality of spacer blocks 39 are adjacent a combination crank and counter-balanced theend of the body or crank 33. These weights weight made up as a single unit which may be are each provided with atongue 40 to engage with adjusted as to length. a suitable groove in the next weight so that they Another object of the invention is to provide will all be clampedsecurely together. 25 a counter-balanced crank which is made up of In order that the base may be built up to,

- a p u al f i d p d sections ap to provide the necessary counter-balancing action, be clamped together to form the crank and couna plurality of plates 42 are arranged to seat on tor-balance. ,each of the ears 43 of the base 35.

' vide a Cou te -ba e We ht attachment for particularly noted that the bolts I5 are arranged Crank arm Such t at t Weight D O y e to pass into the slots or grooves 45 formed in one e d y de d o the crank p t o side of the body 33. The upper end of these It is also an object of the invention to provide d pass through a cover plate 46 so that a 35 a Cou t r-ba a d Weight tt t to the uniform pressure may be exerted upon the end 35 crank arm such that the counter-balance may of th body wh n the device isin operative p0- be removed by being detached laterally from the itio V crank arm- I When it is desired to service the well or use the Other and further objects of the invention will pumping it power independently of the crank b r adily pp when the w ng descriparm and walking beam it is usually desirable to 40 tion is considered in connection with the accomremove the counter-weight so' that it will not Panying drawings wherein: interfere with the use of the crank arm. To ac- 1 S WS a levation of the invention complish this with the Fig. 1 form of the invenwherein the lengt o the Crank may be changed tion it is only necessary to loosen the nuts 48 and positioning of the weights may be adjusted on the ends of the through bolts I5, so that the 45 by adding suitable plates thereto. 7 bolts may be moved laterally around to the right, Fig. 2 is a section taken on the line 2-2 of Fig. as viewed in Fig. 2, and in this manner release 1 and looking in the direction of the arrows. the counter-weight entirely from the crank arm. Fig. 3 shows a modification of the invention The crank can then be rotated during the serv- 50 wherein the device is spaced from the end of the icing operation at a higher rate of speed. 50 crank and fixed in the desired counter-balancing Figs. 3 and 4 show another modification of the position while it encloses or is fixed firmly with invention, wherein the crank body is illustrated at respect to the crank arm. 50 and is provided with the upper and lower Fig. 4 is an edge view of the 3 form of the caps 5| and 52 through which the bolts l5 are 55 invention. adapted to pass. These caps serve to hold the 55 bolts in position within the openings ,52 and 53 formed in the sides of the crank somewhat similar to the openings or grooves in the Fig. 1 form of the invention. 7

It will be noted that the caps have an interfitting boss and socket construction at 55 so that they will be properly centered and firmly held in position. The bolts l5 are modified somewhat in this form of the invention and are provided with the shoulders 56 so that the cap 52 may be drawn tightly against the end of the crank by manipulation of the nuts 51.

The counter-weight is indicated generally at 69 and includes'the base GI and the plates 62, as well as the counter-weight head 63., These parts are interfitting as at 64 and are arranged to be fixed on the rods l5 by means of the adjustable nuts 66 and 61. It will be apparent that these nuts 66 and 61 may be adjusted along the bolts so that the base, plates, and head of the counter-weight may be adjusted longitudinally of the crank arm to obtain the desired counter-balancing action. To secure the adjust- An eye 10 has been shown on the cap 5| so that when the nuts 5'! are loosened and the bolts [5 moved away from crank a suitable hoist may be connected to the bolts, caps and weight, so that the device may be handled conveniently, or moved to a position such that it will not interfere with the rotation of the crank .50 during the servicing of the well.

WVhile two specific forms of the invention have been disclosed, it is to be understood that the invention is not confined thereto, but that changes may be made in the construction and combination of parts without departingfrom the spirit of the invention.

Whatis claimed is:

A counterbalance crank arm for well pumping units comprising an arm body for attachment to the crankshaft of the unit, wrist pin openings therein, a groove the length of said body disposed ateach edge of the body, a rod disposed in each groove, a cap plate across one end of said body through which said rods pass, a plurality of spacer bars at th'eother end of said body, and on said rods, a base weight in Which theends of said rods are anchored and which is positioned below saidspacer bars, and nuts on said rods to bear against said cap plate to hold the parts assembled but adapted for re lease whereby said rods may be moved laterally out of said grooves to remove the Weight from said crank body.

WALTER C. 'TROUT. 

